1 # atomic builtins are required for threading support.
3 INCLUDE(CheckCXXSourceCompiles)
5 check_library_exists(atomic __atomic_fetch_add_4 "" HAVE_LIBATOMIC)
7 list(APPEND CMAKE_REQUIRED_LIBRARIES "atomic")
10 CHECK_CXX_SOURCE_COMPILES("
16 volatile LONG val = 1;
18 InterlockedCompareExchange(&val, 0, 1);
19 InterlockedIncrement(&val);
20 InterlockedDecrement(&val);
22 volatile unsigned long val = 1;
24 __sync_val_compare_and_swap(&val, 1, 0);
25 __sync_add_and_fetch(&val, 1);
26 __sync_sub_and_fetch(&val, 1);
32 if( NOT LLVM_HAS_ATOMICS )
33 message(STATUS "Warning: LLVM will be built thread-unsafe because atomic builtins are missing")